1. Field of the Invention
This invention relates to a cartridge autochanger.
2. Related Background Art
A cartridge auto-changer (hereinafter referred to as the CAC apparatus is an apparatus) which chiefly comprises a cartridge container portion containing therein a number of cartridges (including cassettes) address-arranged, a conveying mechanism including a cartridge hand (catching and liberating) mechanism, and an apparatus operation control circuit including necessary cartridge designating means, and automatically executes operations such as search and extraction of a designated one of the numerous cartridges within the cartridge container, conveyance of the designated cartridge to the cartridge mounting portion (predetermined port) of an instrument used for cartridge mounting and mounting of the necessary cartridge onto the cartridge mounting portion, and return conveyance and recontainment of the used cartridge. It is an apparatus which automatically effects the operation of searching for a designated desired cartridge of a number of microfilm cartridges. These cartridges are address-arranged and contained one by one in number of shelf portions of a rotatable drum shelf type cartridge container. This is done, for example, by catching the cartridge by a hand mechanism, conveying the cartridge to the cartridge mounting portion of a microfilm instrument such as a microfilm reader or a microfilm reader printer and mounting the cartridge onto said cartridge mounting portion. The operation of catching the cartridge used on the microfilm instrument side by the hand mechanism, conveying the cartridge back to a predetermined containing shelf of the container and recontaining the cartridge in said predetermined containing shelf, is done by an apparatus effective in making efficient use of microfilm.
For the sake of convenience, description will hereinafter be made, for example, of a CAC apparatus for automatically mounting a microfilm cartridge onto the car mounting portion of a main apparatus such as a reader.
The conveyance of a necessary cartridge to the cartridge mounting portion of the main apparatus such a the reader and the mounting of the cartridge onto the cartridge mounting portion, by the CAC apparatus, must always be effected with the cartridge being caught by a hand mechanism in a posture wherein the cartridge regularly mounted on the mounting portion. That is, the cartridge must be in a posture in which the cartridge just faces the mounting portion in all of the regular longitudinal directions, the left to right direction and the front to back direction.
When the cartridge is conveyed to the mounting portion while being caught in its improper posture by the hand mechanism, the cartridge interferes with the mounting portion and is not or cannot be smoothly inserted thereinto. If the cartridge is inserted with its longitudinal direction reversed, or with its sides facing laterally or with its front and back surfaces inverted, the film feeding operation on the side of the main apparatus such as the reader will not be accomplished.
Actually, however, it is often the case that the cart ridge is conveyed to the mounting portion of the main apparatus, such as the reader, while being caught in its improper posture by the hand mechanism. For example, if the posture of the cartridges contained on the individual containing shelves of the cartridge container portion is obliquely laterally facing beyond a certain degree relative to the regular posture due to the operational vibrations or the like of the apparatus, the cartridges are liable to be caught in their obliquely laterally facing improper posture by the hand mechanism. Also, when cartridges are to be initially address-arranged and placed into the containing shelves of the cartridge container portion, or when cartridges are supplied into empty shelves, some of the cartridges are contained with their longitudinal direction reversed or with their sides facing laterally or with their top and bottom inverted. If such cartridges are left as they are, those cartridges will be caught in their improper posture such as reversed longitudinal direction, lateral direction or inverted posture by the hand mechanism.
Also, the catching of a desired cartridge by the hand mechanism is accomplished by the pair of hands of the hand mechanism being held open over the grip width of the cartridge. In this state, the hand mechanism is moved forward relative to the desired cartridge so that the cartridge is received between the opened hands. The hands are closed to hold the cartridge therebetween. Then, the hand mechanism is moved in a rearward direction whereby the desired cartridge caught by the hand mechanism is drawn out of the containing portion and conveyed to the cartridge mounting portion of the reader or the like. The cartridge is then returnconveyed to the containing shelf from the cartridge mounting portion. The conveyance (including the return conveyance) of the cartridge is generally executed by the cooperation among a vertically moving mechanism, a cocking mechanism and a pivotally moving mechanism for the hand mechanism which are provided in addition to a forward and rearward moving mechanism for the hand mechanism.
The hand mechanism as described above has often experienced a trouble that the caught object to be gripped slips off from between the hands and falls in the conveyance process thereof. This may be attributed to a vibration, disturbance to the phenomenon that due to the vibration, disturbance or the like of the apparatus. The hands in their closed state sway in the opening directions against their closing forces and the catching forces of the hands with respect to the object to be gripped fluctuate vibrationally.
So, with vibrational force or the like of the apparatus which acts on the hands being taken into account, a countermeasure is adopted, such as setting the catching forces of the hands to a considerably strong level or attaching high-friction elastic members as anti-slippage means to the hands and catching the object to be gripped between those high-friction elastic members.
However, the former method of setting the catching forces to a strong level gives rise to the necessity of corresponding increasing the strength of the components, which in turn leads to a secondary disadvantage such as bulkiness and increased weight of the apparatus.
The latter method of adding the high-friction elastic members has suffered from the fast reduction in the frictional property and elasticity of those numbers resulting from adherence of dust thereto, stain, aging the like thereof, and the variations in the frictional property and elasticity of those members resulting from temperature change, and had a low reliability because of the numerous unstable factors.
Further, the catching of a desired cartridge by the hand mechanism is accomplished by the hand mechanism. The desired cartridges are moved together (generally the hand mechanism being moved forwardly toward the desired cartridge) with the pair of hands of the hand mechanism being held open over the grip width of the cartridge, the cartridge being thus received between the opened hands. The hand mechanism and the desired cartridge are moved together by a predetermined amount, and thereupon the hands are closed and the cartridge is received and held between the hands. Thereafter, conveyance of the desired cartridge caught by the hand mechanism is executed by the operation of a carrier mechanism holding the hand mechanism.
The conventional hand opening-closing mechanism has been of the link type, the rack-pinion type, the gear-cam type or the tension wire type. The link type has suffered from problems such as low efficiency of force transmission and increased weight and increased cost of the apparatus resulting from an increased number of parts. The rack-pinion type and the gear-cam type have suffered from problems such as the additional time required for the adjustment of the amount of opening-closing of the hands and the difficulty encountered in effecting such adjustment. The tension wire type is low in reliability due to the strain on the wire and requires a great amount of wire pulling stroke. This greatly hampers compactness and light weight of the hand mechanism.